The significant part of the electrohydraulic brake devices which are used today in series production in motor vehicles is still composed at least of an activation boost apparatus (booster) with a usually hydraulic or pneumatic brake boosting means and a compact electrohydraulic pressure open-loop or closed-loop control assembly (HECU) which is arranged separately therefrom.
Electrohydraulic brake control devices with travel sensors for sensing the activation travel of a brake rod, in which the travel sensor is arranged structurally separate from, or at least on the outside of, the housing of the electronic control unit (ECU), have already become known. Corresponding arrangements with the travel sensor system are known, for example, by the term hydraulic “brake-by-wire” brake. A travel sensor arrangement suitable for this can be found, for example, in DE 100 10 042 A1, which is incorporated by reference.
DE 10 2004 058 875 A1, which is incorporated by reference, also describes a travel sensor which operates in a contactless fashion for an electrohydraulic brake which operates according to the Hall principle. The sensor magnet is directly positioned on the piston. The actual measuring pickup of the travel sensor is arranged outside on the housing of the pressure-generating unit or pressure-boosting unit.
The brake devices described above have spatial separation of the pressure-generating or -boosting device (booster) from the pressure open-loop or closed-loop control unit. This is also the case in a “brake-by-wire” brake where the pedal module together with a pedal sensation simulator is also separate from the actual brake pressure control device. To an increasing degree, there are now efforts also to include, in relatively large parts of the series, brake devices which overcome the spatial separation of the activation and open-loop or closed-loop control of the pressure by combining the electrohydraulic components to form one combined assembly. Even if such arrangements have already become known per se, there is still the possibility of making further improvements with respect to the requirements of the automobile industry in terms of flexibility, braking power and comfort while complying with the manufacturing budget which is available for it.